[A case of adrenal lipoma]

Lipoma of the adrenal gland is extremely rare. This condition was first described in 1988 and only seven cases have been reported to date. We have experienced a case of adrenal lipoma which was thought to be adrenal myelolipoma on computed tomography (CT). A 56-year-old man was admitted to our department with a complaint of left abdominal pain. Sonography revealed a hyperechoic mass above the left kidney, and a CT scan revealed the mass to be comprised sharply marginated and an inhomogeneous structure. The tumor was comprised of areas of different density including a fatty tissue portion. These findings were strongly suggestive of adrenal myelolipoma or liposarcoma, and a left adrenalectomy was performed. Macroscopically, the tumor was consisted of yellow fatty mass and necrotic areas, which were surrounded by thin fibrous capsule. The adrenal gland was compressed at the bottom of the tumor. The weight of tumor was 290 g. Microscopically, the tumor consisted of large fat cells in direct contact with adrenal cortical cells, and it was then diagnosed adrenal lipoma. Postoperatively, the patient no longer experienced left abdominal pain and there has been no recurrence in the 31 months since the operation.